Cokeromyces recurvatus, a sporangiola-forming dimorphic fungus, is a rare cause of urogenital infection in humans. We report here a case of severe watery diarrhea due to C. recurvatus, which was treated successfully with high-dose oral nystatin therapy. We speculate that our patient was probably predisposed to infections due to opportunistic organisms, such as C. recurvatus, because of post-transplantation immunosuppression. To our knowledge, our patient represents the first documented case of diarrhea due to C. recurvatus in man, and this case highlights the potential pathogenic capability of this opportunistic organism in immunosuppressed patients.